Plagiarism Lab

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Word Count: 908 words Plagiarism check : 98% Paragraph 1: The main focus of the research paper revolves around the changes in the structure of the chemical compound FePO4, in environment of different temperatures ranging from 294K to 1073K. Generally, at lower temperature (which is 294K in this case), the chemical compound will take a tetrahedral structure, which is known as the α-quarts. This is also know as the α- phase when FePO4 takes the tetrahedral structure. As the temperature increases and the pressure increases, FePO4 will experience a structural change and shift into what we known as the β-phase, where the compound will know take on a more dense octahedral shape. The exact temperature where this change will occur is at 980K. During the α-phase, the…show more content…
Both structures contains a 1 formula unit in a unit cell, with α- FePO4 having a trigonal unit cell while β- FePO4 having a hexagonal unit cell. This will also lead us to the main difference between the symmetry between α- FePO4 and β- FePO4, where the symmetry of α- FePO4 is trigonal while the symmetry of β- FePO4 is hexagonal. As the temperature increases, the volume and cell parameter also increases. There will be a preferential directional expansion (which mean they will expand towards the same direction), so the c/a ratio will drop as the temperature increases. The Fe-O-P bond will start to bend and it will expand significantly. T=650K (when volume and parameter increased) As temperature approaches the transition temperate which is at 980K, the parameter of the structure of the compound will start its transformation from that of the low temperature α- FePO4 structure to a high temperature β- FePO4 structure. The tilt angle δ can be observed to drop sharply as the temperature approaches 980k. In β- phase, the temperature will not have a significant impact on both the bond distance between Fe-O-P and the bond…show more content…
T=1000K (when the temperature do not have an impact anymore) This table below depicts and emphasizes the point where the tilt angles will decrease as the temperature increases, till it past the transition temperature. Paragraph 3: Basically, the structure of FePO4 is constructed by tetrahedral rings made up of (FeO4) and (PO4). When the temperature of its surrounding increases, this will lead to a tetrahedral distortion. The changes in lengths of the bonds present in the compound (O-Fe-O) and the tetrahedral tilt angles, due to the compound reaction to the changes in temperature, is the cause of this distortion. This will result in the cell parameters and the volume of the compound FePO4 to increase when the temperature increases but in a non-linearly manner. The tilt angles can actually be calculated out using the temperature dependence model as shown above previously: δ 2 =2/3δ0 2 [1+(1–3⁄4(T–Tc/T0 –Tc))^1/2] Where δ0 is the drop in tilt angle at the 980K (transition temperature) and Tc is the temperature for the second-order transition. As the compound reaches the

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